Tomato Spotted Wilt Virus Benefits a Non-Vector Arthropod, Tetranychus Urticae, by Modulating Different Plant Responses in Tomato

Abstract

The interaction between plant viruses and non-vector arthropod herbivores is poorly understood. However, there is accumulating evidence that plant viruses can impact fitness of non-vector herbivores. In this study, we used oligonucleotide microarrays, phytohormone, and total free amino acid analyses to characterize the molecular mechanisms underlying the interaction between Tomato spotted wilt virus (TSWV) and a non-vector arthropod, twospotted spider mite ( Tetranychusurticae ), on tomato plants, Solanum lycopersicum . Twospotted spider mites showed increased preference for and fecundity on TSWV-infected plants compared to mock-inoculated plants. Transcriptome profiles of TSWV-infected plants indicated significant up-regulation of salicylic acid (SA)-related genes, but no apparent down-regulation of jasmonic acid (JA)-related genes which could potentially confer induced resistance against TSM. This suggests that there was no antagonistic crosstalk between the signaling pathways to influence the interaction between TSWV and spider mites. In fact, SA- and JA-related genes were up-regulated when plants were challenged with both TSWV and the herbivore. TSWV infection resulted in down-regulation of cell wall-related genes and photosynthesis-associated genes, which may contribute to host plant susceptibility. There was a three-fold increase in total free amino acid content in virus-infected plants compared to mock-inoculated plants. Total free amino acid content is critical for arthropod nutrition and may, in part, explain the apparent positive indirect effect of TSWV on spider mites. Taken together, these data suggest that the mechanism(s) of increased host suitability of TSWV-infected plants to non-vector herbivores is complex and likely involves several plant biochemical processes.

Salicylic Acid Is Involved in the Basal Resistance of Tomato Plants to Citrus Exocortis Viroid and Tomato Spotted Wilt Virus

“…Tomato plants inoculated with TSWV also results in the establishment of a compatible interaction, however the accumulation of phenolic compounds in this system has not yet been fully explored [11, 12]. …”

Alterations in rice, corn and wheat plants infested by phytophagous mite

“…Genes involved in cellular detoxification are also up-regulated, signalling for the production of antioxidant enzymes such as peroxidases, catalase and superoxide dismutase (Grinberg et al 2005;Nachappa et al 2013). Through a combined metabolomics and transcriptomics approach, Kant (2004) showed that one day after infestation by TSSM on tomato leaves, direct defence responses (such as proteinase inhibitor activity and transcription of genes involved in JA-, SA-, and ethyleneregulated defences) had already been activated.…”

“…The primary metabolism of infested plants is disturbed, specifically changing the metabolism of amino acids and carbohydrates, as well as changing the hydric potential of their cells. Nutrient transportation can also be interrupted to hinder feeding, but this is not always effective (Nachappa et al 2013).…”

Physiological and Molecular Alterations Promoted by Schizotetranychus oryzae Mite Infestation in Rice Leaves

“…Gaseous phytohormones, such as ethylene and a series of terpenes, as well as jasmonic acid (JA) and salicylic acid (SA) 14 are released by plants and regulate several defense signaling mechanisms 12 . Genes involved in cellular detoxification may also be up-regulated, signaling for the production of antioxidant enzymes 15 .…”